Tilt Train U. S. Department Technology: of Transportation A State of the Art Federal Railroad Administration Survey Moving America May 1992 New Directions, New Opportunities 1 - Advanced Systems NOTICE This document is disseminated under the sponsorship of the Department of Transportation in the interest of information exchange. The United States Government assumes no liability for its contents or use thereof. NOTICE The United States Government does not endorse products or manufacturers. Trade or manufacturers' names appear herein solely because they are considered essential to the object of this report. NOTICE In numerous places, this report discusses whether various aspects of the technology that is the subject of this report comply with Federal safety laws and regulations. Those discussions, which reflect the seasoned judgement of commentators qualified in their fields, do not constitute rulings by the Federal Railroad Administration's Office of Safety or its Office o f Chief Counsel concerning compliance with the law. FOREWORD Many intercity high-speed train technologies have become an operating reality in recent years. Though mostly of foreign origin, these new trains offer the potential for immediate application in the United States. Each high-speed train was developed to meet the particular operating environment appropriate to the parent country’s transportation policy. The resulting diversity in design concepts permits the consideration of a variety of systems in meeting various U.S. application requirements. One particular design concept, the tilt-train technology, offers opportunity for application over the existing rail infrastructure. This executive summary and its companion report, one in a series of reports which describe new high-speed rail technologies, presents an overview of the state-of-the-art in tilt-train technology. It is intended to give the reader a better understanding of the unique features of this approach to train design and the variations that exist. Briefly described is the function of the tilting mechanism, whether passive or active, and its performance with respect to passenger ride quality, safety and trip times, which are all influential in passenger acceptance and modal choice. Two trains of the type described in this report, the Spanish Talgo Pendular and the Canadian LRC, were previously tested by Amtrak on the Northeast Corridor (NEC), though not used in revenue service. Currently being considered for test and revenue service in the NEC is the Swedish X2000, also covered in this report as well as in an earlier report on the Safety Relevant Observations on the X2000 Tilting Train. A more comprehensive review of the state-of-the-art in tilt-train technology appears in the companion report which expands upon the technical relevance of the tilt-train technology and its proper perspective with respect to safety. This state-of-the-art report is not intended to be evaluative in nature, but rather to inform the reader of the considerations that may be appropriately directed to this form of high-speed rail. Many Americans have had the opportunity to ride on the new families of high-speed trains operating in Europe and Japan, the TGV, the ICE, the X2000, the Pendelino, the Talgo, and the Shinkansen. Now, it is time to begin "Moving America" on high-speed, intercity, guided ground transportation. The future prospects have never looked better and the Intermodal Surface Transportation Efficiency Act of 1991 has laid the foundation with new opportunities for demonstration projects with federal support. 1 ACKNOWLEDGEMENT This report was prepared for the Volpe National Transportation Systems Center (VNTSC) in support of the United States Department of Transportation (U.S. DOT), Federal Railroad Administration’s (FRA) Office of Research and Development. The authors, Chris J. Boon (Canadian Institute for Guided Ground Transport) and Brian T. Whitten (ENSCO, Inc.) wish to thank Robert M. Dorer and Stephanie H. Markos of VNTSC and Arne J. Bang of the FRA Office of Research and Development, for their direction, helpful guidance and input during the preparation of this document. The authors also wish to thank William O’Sullivan and Gordon David of the FRA Office of Safety, and Herbert Weinstock, Michael Coltman, and Harvey Lee of VNTSC for providing reference material, important input and critical review. Arthur H. Rubin of EG & G Dynatrend, Inc. provided editorial support. 111 TABLE OF CONTENTS Section Page Introduction......................................................................................... 1 Curving Mechanics ............................................................................. 3 Negotiating a Curve: Some Simple Physics............................. 3 Why Tilt the Vehicle? Why Not Change the Superelevation?............... 7 The Trade-offs of Tilting Trainsets.................................. 8 Achieving Deliberate Body T i l t ......................................................... 11 Passive-Tilting.................................................. 11 Active-Tilting.................................................. 13 Curve Detection and Tilt Actuation.................................. 14 Fail-safe and Fault-tolerant Design.................................. 18 Reliability and Maintainability..................................... 18 Cost versus Performance: How Tilting Affects This Fundamental Tradeoff.... 18 Summary of Safety Considerations: What Tilting Does and Does Not Affect... 20 Overview of Tilt-Body Technologies .............................................. 23 Previous U.S. Experience with Tilt-Body Technologies.............. 27 Early Experience with LR C ........................................ 27 Banking Amcoach............................................... 28 C O N E G Tests................................................... 28 Conclusions from U.S. Tilt-Body Train Experience....................... 31 Tilt Operations in the U.S. - Issues and Opportunities ............... 33 Body Tilting Issues............................................... 33 Increased Curving Speed and Operating Safety......................... 34 Vehicle Overturning........................................... 34 Wheel Climb.................................................. 36 Gage Widening................................................ 36 Lateral Track Shift............................................ 37 Compatibility With Clearance Envelopes for Existing Lines and Equipment.... 38 Maintainability and Reliability..................................... 39 Effects of U.S. Alignment Geometry and Track Maintenance Standards....... 43 The Incremental Costs and Benefits of Tilting.......................... 44 Overview of Safety Issues, for Equipment Not Designed to U.S. Standards..... 44 Sum m ary.............................................................................................. 47 Endnotes 49 LIST OF FIGURES Figure Page 1 Accelerations and Forces Acting During Curving...................... 4 2 Effect of Suspension Compression on Forces Acting on Passengers During Curving........................... 6 3 Effect of Deliberate Body Tilting on Forces Acting on Passengers.......................................... 7 4 Location of Carbody Roll Center and Center of Gravity for Passive and Active Body Tilting...................... 11 5 The Talgo Passive-Tilt Coach..................................... 12 6 The JR-Shokaku Series 381 Passive-Tilting Narrow-Gauge EM U .......... 13 7 The LRC as Produced for Via Rail Canada, Inc........................ 14 8 The Fiat Ferroviara ETR-450 Active -Tilt EM U Trainset................ 15 9 The ABB X2000 Active-Tilting Trainset............................. 16 10 Alternative Sensor Locations for Active Body Tilt Control Systems........ 17 11 Vehicle Suspension Configuration................................. 19 12 Comparison of Carbody Lateral Acceleration Trend Lines............... 30 13 Northeast Corridor Construction Limit Outline, LRC Prototype Car, Maximum Tilt............................... 40 LIST OF TABLES Table Page 1 Comparison of Maximum Axle Load and Unsprung Mass.............. 20 2 Active Tilt Technologies....................................... 24 3 Active Tilt Technologies-Conceptual Designs....................... 25 4 Passive Tilt Technologies...................................... 26 5 X2000 Preventative Maintenance Schedule and Requirements.......... 42 6 Scheduled Maintenance Activities-Amfleet Cars..................... 43 vi INTRODUCTION This report presents a survey of the and technical characterizations of each of technical and operational features of the technologies are given in a companion existing and planned tilt-body rail to this report.1 passenger vehicles. It follows the general format of the December 1990 Federal In preparation of this report, information Railroad Administration (FRA) Report was drawn from public sources. Technical entitled, "Safety Relevant Observations on and illustrative material was also requested the X2000 Tilting Train," (DOT/FRA/ from the developers, suppliers, and ORD-90/14; NTIS: PB 91-12-9668) but with operators of the different technologies. The a broader scope. variable level of detail in the technical descriptions and characterizations reflects The most significant implications of tilt- differences in the availability of such body technologies are for the tradeoffs and information. The data in the public domain compromises that have been, and continue were identified through on-line searches of to be made between